Separator for storage-battery electrodes



Nov. 16 1926.

J. P. WILBURN Filed Feb. 1 1923 SEPARATOR FOR STORAGE BATTERY ELECTRODES 2 Sheets-Sheet 1 glwmwbtoi:

16,1926. Nov J. P. WILBURN 1607496 SEPARATOR FQR STORAGE BATTERY ELECTRODES Filed Feb. 1, 1923 2 Sheets-Sheet 2 Patented Nov. 16 1926.

UNITED STATES PATENT OFFICE.

JOHN P. WILBURN, OF INDIANAPOLIS, INDIANA, ASSIGNOR TO THE PREST-O-LITE COMPANY, INC., A CORPORATION OF NEW YORK. I

SEPARATOR FOR STORAGE-BATTERY ELECTRODES.

Application filed February 1, 1823. Serial No. 616,388.

This invention relates to separating means for storage battery electrodes. A'particular object of the invention is to provide an improved combination separator comprising a sheet of wood or composition material protected on one or both sides by an auxiliary spacer composed of a strong, acid-resisting material.

It is well known that the advantages of separators made from wood, wood pulp, or the like, are con led with certain objectionable features. gne of the chief ob ections is the low mechanical strength of the separator, especially after it has stood for some time in contact with the electrolyte. Warping or buckling of the electrode plates exerts a pressure which the separator is unable to withstand, and in consequence the distorted plates come into contact with those adjacent to them, resulting in shortcircuits which impair or destroy the effectiveness of the battery.

Further, if wooden separators are placed so as to rest against the lead peroxid plate, they are subject to rapid deterioration.

In the endeavor to protect such separators from destructive pressure and. disintegration by the active agents of the battery, it has heretofore been proposed to adopt the general combination of wooden separator and protective means referred to above. This has in general taken the form of a perforated sheet of hard rubber placed on one or both sides of a ribbed wooden separator.

According to the preferred embodiment of the present invention, a strong, inert auxiliary separator, in the form of a frame having connecting and strengthening members occupying a relatively small or minor part of the space which it defines, is used with plane wooden separators, which are preferably arranged with the grain running horizontally. Important advantages result from this new construction and arrangement, as will be clear from the following description.

Reference is. to be made to the accompanying drawings, in which- Fig. 1 is an elevation of an auxiliary spacer;

Fig. 2 is a perspective view, partly broken away, showing the auxiliary spacer of FigT 1 assembled with wooden separators and an I electrode;

Fig. 3 is an elevation of a spacer adapted to Engage both faces of an electrode plate, an

Fig. 4 is a vertical transverse section on l1ne IVIV, Fig. 3.

Referring to Fi s. 1 and 2 of the drawlngs, numeral 1 enotes a frame of relatively strong material, not subject to deterioration in acid electrolyte. Hard rubber is the preferred material; but celluloid or other equivalents may be used. The top and bottom of the frame are connected by intermediate integral strips 2 of small area. The strips may of course be disposed in other ways than that shown.

The base of the auxiliary spacer so formed is preferably provided with indentations 3 adapted to receive the brid es used to raise the plates and separators rom the bottom of the battery jar. Openings 4 are thus lef't' adjacent to the lower margins of the positive plate 5 and negative plate 7 (Fig. 2) and through these openings active material dislodged from the plates may pass into a sediment space beneath the electrode assembly. Circulation of electrolyte. is also materially facilitated by the downward extension of the auxiliary spacer in the mafiner described. Free diffusion is also obtained at the top of the elements due to the open spaces 8 and 9.

An auxiliary spacer 1 is placed on each side of the positive electrode 5. Plane or uncorrugated wooden sheets 6 rest against the auxiliary separators and are spaced" thereby from the electrode. The detrimental action of the positive active material is substantially avoided by this arrangement. The negative plates 7 only one of which is shown, may be placed in direct contact-with the wooden sheets, as the wood is not harmed this respect the present invention is distinguished from the prior art referred to above,

in which finely perforated hard rubber sheets are placed in protective relation to wooden, separators. Ribbed separators are necessary under such conditions.

Theelimination of the ribbing operation is of marked advantage from the commercial standpoint. In addition, since a plane surfaced wooden separator may be used, the grain of the wood may extend either horizontally or vertically. It will be understood that the horizontal grain arrangement is not practical with ribbed separators, for the reason that the ribs must extend vertically in the battery, and this would necessitate cutting the ribs across the grain of the wood.

Ihave found that the horizontal grain arrangement is preferable, because the tendency for the separator to be warped 0r deflected into contact with the positive plate is great ly reduced by this arrangement. Referring to Fig. 2 it will be apparent that the possibility of the separator 6 becoming distorted to such an extent between the ribs 2 that contact will result between the positive plate 5 and the separator 6 is very slight. However, if separator 6 were turned throughan angle of 90 degrees to bring the grain of'the wood'into a vertical position, there would be a probability of contact being established between the separator 6 and positive plate 5.

InFigs. 3 and 4 an auxiliary spacer 8, of a type generally similar to that described, is illustrated. This spacer comprises parallel frames 9 and 10, each having reinforcing connecting strips '11. The frames are connected at the bottom by suitable means. A double or folder type of spacer is thus produced.

In the form of the invention illustrated, the spacer is made from an integral hard rubber blank, the median portion 12 of which is retained to serve as a connection between the two frames 9 and 10. A positive electrode may be placed within the double spacer, which will serve to keep the wooden separating sheets at the. proper distance separator. In this way the same advantages are secured.

Auxiliary spacers of the type shown in Fig. 1 may be made in double form also, if

desired. In either form of the inyention, the spacers may be made by 'moldin rubber or other suitable material into t e desired shape, or they may be cut from sheet stock, or otherwise suitably formed.

Instead of wooden separators, other spacing means, normally not suificiently strong and acid-resistant, may be used in combination with the protecting frames described. For example fabricated sheets of cellulosic fibers or the like ma be so used.

In electrode assem lies comprising the improved auxiliary spacers, the separator sheets are afforded proper protection against failure owing to pressure exerted by the plates and are also effectively prevented from injuriouscontact with the positive electrode. At the same time, ade uate circulation of electrolyte and proper isposal of sloughed active material is insured.

These and other advantages of the novel construction are not dependent upon the specific 'forms of the invention illustrated, and

various modifications may be made therein without sacrificing such advantages or exceeding the scope of the appended claims.

I claim 1. In combination with a positive lead storage battery electrode and plane uncorrugated wooden separator sheets, auxilia spacers interposed between the electro e and the wooden sheets, said auxiliary spacers each com rising an inert, acid-resistant frame having members occupying a minor portion only of the space defined by the frame and connecting opposed sides thereof.

2. The invention accordin to claim 1, in which the auxiliary spacers extend beyond the margin of the electrode and are provided with openings facilitatin circulation of electrolyte and passage of islodged active material.

3. The invention according to claim 1, in which the auxiliary separators extend above and below the electrode and are provided with openings facilitating circulation of electrolyte and passage of dislodged active material.

4. The invention according to claim 1, in which the wooden separator sheets are arranged with thegrain running horizontally of the battery. from the electrode and thus removed from 5. In combination, a storage battery elec trode, a wooden separator having plane surfaces and the grain running horizontally,

and auxiliary spacing means independent of the wooden separator and spacing itfrom the electrode.

6. In combination, an electrode plate, spacing means in contact with said late and extending beyond the margin of t e same, and a wooden separator abutting against the spacing means, the extended portions of the spacing means having openin through which dislodged active materia may pass and through which free difi'usion may take I place. 7.

In a storage battery, the combination of positive electrodes, negative electrodes,

'plane uncorrugated separators between said positive and negativeelectrodes, and auxiliary spacers disposed against said separators, each spacer comprising a plurality of connected electrolyte-resistant members extending above and below said electrodes and occupying a minor portion only of the face of the adjoining separator so as to leave openings for difiusion of electrolyte and 'for passage of dislodged active material and also to leave themajor portions of such separator faces exposed to electrolyte.

In testimony whereof, I aifix my signature.

JOHN P. WILBURN. 

